INHALED INDUCTION AND EMERGENCE FROM DESFLURANE ANESTHESIA IN THE AMBULATORY SURGICAL PATIENT - THE EFFECT OF PREMEDICATION

We studied the effect of premedication (1 mug/kg fentanyl and 0.04 mg/ kg midazolam 5 min before induction of anesthesia) on airway reactivit y and hemodynamic stability during inhaled induction using desflurane in 10 ambulatory surgical patients. Eight patients who were anesthetiz ed without premedication served as the controls. Induction and emergen ce were rapid and unaffected by premedication. End-tidal and inspired concentrations of desflurane at loss of consciousness were significant ly reduced by premedication (10.1% end-tidal/14.1% inspired, no premed ication, vs. 5.3% end-tidal/8.9% inspired, premedication). Airway irri tability was markedly attenuated by premedication (100% no premedicati on versus 30% premedicated), as was apnea (37.5% no premedication vers us 0% premedicated). We observed an increase in mean arterial blood pr essure and heart rate after loss of consciousness (mean arterial press ure 103 vs 121 mm Hg, heart rate 73 vs 100 bpm) in the unpremedicated patients, whereas both groups demonstrated a decrease in mean arterial blood pressure with no change in heart rate when baseline values were compared to those at incision (103 vs 74 mm Hg, no premedication, 99 vs 81 mm Hg premedicated). Patient acceptability was satisfactory and unchanged by premedication. We recommend the use of such premedication when desflurane is used during the induction of anesthesia.